The first step to
becoming a good Blackjack player is what is known the world over as Basic
Strategy. This is the best possible strategy choice of choosing to Stand, Hit,
Split or Double for every possible player's hand against every Dealer's card.
It is correct given just the basic starting information of the game, which are
the rules of the game and the constitution of the deck of cards in use.

Basic Strategy uses a static set of rules and does not include
modifying information the like of which you might get from card counting, card
tracking or any other advanced technique that can be employed to beat the game
of Blackjack. It is also correct whether the house is using conventional
dealers, card shuffling machines or random number generators for machines or
online gaming.

So for example lets choose the most popular mistake made
by players, hard sixteen against the dealers 10, (hard hands are those that do
not include an Ace). Knowing the probabilities of drawing all card combinations
from the deck allows us to calculate by computer simulation that the correct
play is always to take a card. This is true for standard Blackjack rules used
around the world.

Rules matter. With a specific set of rules there is a
specific
Blackjack
basic strategy. Whether you can split, double or the dealer checks for
Blackjacks changes the equity value of your hand and so the Basic Strategy will
fit those values. And blackjack rules change from country to country and even
in places like Las Vegas, from casino to casino. We will look at that
later.

For the purposes of this article we will consider standard UK
rules. Between 4 and 8 decks of cards (usually 6), split any pair and double
anything, dealer stands on soft 17 (Ace + 6) and does not check for Blackjacks
(in the USA and some other places the dealer deals a down card and checks to
see if they have a Blackjack).

Table 1. Splitting strategy
against dealer's card.

1

Dealer's Card

PLAYER

2

3

4

5

6

7

8

9

10

A

2-2

3-3

4-4

5-5

6-6

7-7

8-8

9-9

10-10

A-A

Split

No

Table 2. Doubling Down strategy
against dealer's card.

2

Dealer's Card

PLAYER

2

3

4

5

6

7

8

9

10

A

9

10

11

Double

No

Table 3. Draw, Stand and Double
strategy on soft totals.

3

Dealer's Card

PLAYER

2

3

4

5

6

7

8

9

10

A

13

14

15

16

17

18

19-20

Double

Draw

Stand

Table 4. Draw and Stand strategy
for hard hands.

4

Dealer's Card

PLAYER

2

3

4

5

6

7

8

9

10

A

4-11

12

13-16

17-20

Draw

Stand

Playing with these rules
and this optimal Basic Strategy then the House Edge is 0.51%. If the dealer
were allowed to hit soft 17 then this rises to 0.73%. However if the dealer
checks for Blackjacks (which allows us to split 8s vs 10 and Ace, split Aces vs
Ace and doubling of 11 against a 10) then the House Edge drops to
0.40%.

So starting with our base of House Edge +0.51% lets see what
happens if the house changes the rules;

Dealer checks for
Blackjack -0.11%

Four decks -0.1%

Eight decks +0.03%

Can only split once
+0.05%

Restrict Doubling Down
to 9,10 and 11 +0.1%

No Doubling Down on
soft totals +0.1%

Can't double after
splitting +0.1%

Dealer hits soft 17
+0.22%

Pay Blackjack at 6:5
+1.36%

All of these are rule
variations are possible even in the United Kingdom although some you will never
likely see.